Speaking of actuation the E55 sports steering wheel mounted buttons that connect through to a high-capacity 5-speed automatic transmission with SpeedShift programming, good for a 35% improvement in gear change interval speeds. The transmission can also be prompted to downshift automatically, similar in theory to the Porsche Turbo's Tiptronic. The "Optimum Gear Selection" program uses a complex digital mapping system that chooses the best gear for any given situation, reading vehicle speed plus rates of acceleration, braking and lateral G loads to ascertain the optimal ratio. The 'smart' transmission will also hold the selected gear when experiencing high cornering loads, preventing a potentially dangerous upshift mid-turn. Making performance even livelier, Mercedes has included a lightweight torque converter that has the ability to lock up in all forward gears when needed.
All this speed requires brakes of at least equal stopping performance. The E55 gets Mercedes-Benz's excusive electronic braking system that is standard equipment on all 2003 E-Class models. The new system provides shorter stopping distances, especially in emergencies, with quicker response and better feel from input. How does it work? After pressing the pedal, a variety of sensors feed information to a CPU that in-turn causes four fast-acting valves to apply the brakes as needed to each wheel, via an electrically driven hydraulic pump and high-pressure reservoir. The system has the ability to modify brake pressure at each wheel over uneven surfaces, and when called upon can even increase brake pressure on outside wheels during turns. It all takes place in milliseconds - impressive. It obviously impressed the Canadian Automobile Association's (CAA) judging committee as the 'brake-by-wire' technology won the coveted 2003 CAA Pyramid Award for Safety Innovations, a prize shared with rival Volvo. Incidentally Mercedes-Benz's preventative, protective safety system and roll-over and occupant protection system, both of which are part of the E55 package, were recognized.